package com.springframework.beans;

import org.springframework.beans.Mergeable;
import org.springframework.beans.PropertyValue;
import org.springframework.lang.Nullable;

import java.util.*;
import java.util.stream.Stream;

/**
 * @Author 虎哥
 * @Description //TODO
 * 要带着问题去学习,多猜想多验证
 **/
public class MyMutablePropertyValues implements MyPropertyValues {
    private final List<MyPropertyValue> propertyValueList;

    @Nullable
    private Set<String> processedProperties;

    private volatile boolean converted = false;


    /**
     * Creates a new empty MutablePropertyValues object.
     * <p>Property values can be added with the {@code add} method.
     * @see #add(String, Object)
     */
    public MyMutablePropertyValues() {
        this.propertyValueList = new ArrayList<>(0);
    }

    /**
     * Deep copy constructor. Guarantees PropertyValue references
     * are independent, although it can't deep copy objects currently
     * referenced by individual PropertyValue objects.
     * @param original the PropertyValues to copy
     * @see #addPropertyValues(MyPropertyValues)
     */
    public MyMutablePropertyValues(@Nullable MyPropertyValues original) {
        // We can optimize this because it's all new:
        // There is no replacement of existing property values.
        if (original != null) {
            MyPropertyValue[] pvs = original.getPropertyValues();
            this.propertyValueList = new ArrayList<>(pvs.length);
            for (MyPropertyValue pv : pvs) {
                this.propertyValueList.add(new MyPropertyValue(pv));
            }
        }
        else {
            this.propertyValueList = new ArrayList<>(0);
        }
    }

    /**
     * Construct a new MutablePropertyValues object from a Map.
     * @param original a Map with property values keyed by property name Strings
     * @see #addPropertyValues(Map)
     */
    public MyMutablePropertyValues(@Nullable Map<?, ?> original) {
        // We can optimize this because it's all new:
        // There is no replacement of existing property values.
        if (original != null) {
            this.propertyValueList = new ArrayList<>(original.size());
            original.forEach((attrName, attrValue) -> this.propertyValueList.add(
                    new MyPropertyValue(attrName.toString(), attrValue)));
        }
        else {
            this.propertyValueList = new ArrayList<>(0);
        }
    }

    /**
     * Construct a new MutablePropertyValues object using the given List of
     * PropertyValue objects as-is.
     * <p>This is a constructor for advanced usage scenarios.
     * It is not intended for typical programmatic use.
     * @param propertyValueList a List of PropertyValue objects
     */
    public MyMutablePropertyValues(@Nullable List<MyPropertyValue> propertyValueList) {
        this.propertyValueList =
                (propertyValueList != null ? propertyValueList : new ArrayList<>());
    }


    /**
     * Return the underlying List of PropertyValue objects in its raw form.
     * The returned List can be modified directly, although this is not recommended.
     * <p>This is an accessor for optimized access to all PropertyValue objects.
     * It is not intended for typical programmatic use.
     */
    public List<MyPropertyValue> getPropertyValueList() {
        return this.propertyValueList;
    }

    /**
     * Return the number of PropertyValue entries in the list.
     */
    public int size() {
        return this.propertyValueList.size();
    }

    /**
     * Copy all given PropertyValues into this object. Guarantees PropertyValue
     * references are independent, although it can't deep copy objects currently
     * referenced by individual PropertyValue objects.
     * @param other the PropertyValues to copy
     * @return this in order to allow for adding multiple property values in a chain
     */
    public MyMutablePropertyValues addPropertyValues(@Nullable MyPropertyValues other) {
        if (other != null) {
            MyPropertyValue[] pvs = other.getPropertyValues();
            for (MyPropertyValue pv : pvs) {
                addPropertyValue(new MyPropertyValue(pv));
            }
        }
        return this;
    }

    /**
     * Add all property values from the given Map.
     * @param other a Map with property values keyed by property name,
     * which must be a String
     * @return this in order to allow for adding multiple property values in a chain
     */
    public MyMutablePropertyValues addPropertyValues(@Nullable Map<?, ?> other) {
        if (other != null) {
            other.forEach((attrName, attrValue) -> addPropertyValue(
                    new MyPropertyValue(attrName.toString(), attrValue)));
        }
        return this;
    }

    /**
     * Add a PropertyValue object, replacing any existing one for the
     * corresponding property or getting merged with it (if applicable).
     * @param pv the PropertyValue object to add
     * @return this in order to allow for adding multiple property values in a chain
     */
    public MyMutablePropertyValues addPropertyValue(MyPropertyValue pv) {
        for (int i = 0; i < this.propertyValueList.size(); i++) {
            MyPropertyValue currentPv = this.propertyValueList.get(i);
            if (currentPv.getName().equals(pv.getName())) {
                pv = mergeIfRequired(pv, currentPv);
                setPropertyValueAt(pv, i);
                return this;
            }
        }
        this.propertyValueList.add(pv);
        return this;
    }

    /**
     * Overloaded version of {@code addPropertyValue} that takes
     * a property name and a property value.
     * <p>Note: As of Spring 3.0, we recommend using the more concise
     * and chaining-capable variant {@link #add}.
     * @param propertyName name of the property
     * @param propertyValue value of the property
     * @see #addPropertyValue(PropertyValue)
     */
    public void addPropertyValue(String propertyName, Object propertyValue) {
        addPropertyValue(new MyPropertyValue(propertyName, propertyValue));
    }

    /**
     * Add a PropertyValue object, replacing any existing one for the
     * corresponding property or getting merged with it (if applicable).
     * @param propertyName name of the property
     * @param propertyValue value of the property
     * @return this in order to allow for adding multiple property values in a chain
     */
    public MyMutablePropertyValues add(String propertyName, @Nullable Object propertyValue) {
        addPropertyValue(new MyPropertyValue(propertyName, propertyValue));
        return this;
    }

    /**
     * Modify a PropertyValue object held in this object.
     * Indexed from 0.
     */
    public void setPropertyValueAt(MyPropertyValue pv, int i) {
        this.propertyValueList.set(i, pv);
    }

    /**
     * Merges the value of the supplied 'new' {@link PropertyValue} with that of
     * the current {@link PropertyValue} if merging is supported and enabled.
     * @see Mergeable
     */
    private MyPropertyValue mergeIfRequired(MyPropertyValue newPv, MyPropertyValue currentPv) {
        Object value = newPv.getValue();
        if (value instanceof Mergeable) {
            Mergeable mergeable = (Mergeable) value;
            if (mergeable.isMergeEnabled()) {
                Object merged = mergeable.merge(currentPv.getValue());
                return new MyPropertyValue(newPv.getName(), merged);
            }
        }
        return newPv;
    }

    /**
     * Remove the given PropertyValue, if contained.
     * @param pv the PropertyValue to remove
     */
    public void removePropertyValue(MyPropertyValue pv) {
        this.propertyValueList.remove(pv);
    }

    /**
     * Overloaded version of {@code removePropertyValue} that takes a property name.
     * @param propertyName name of the property
     * @see #removePropertyValue(PropertyValue)
     */
    public void removePropertyValue(String propertyName) {
        this.propertyValueList.remove(getPropertyValue(propertyName));
    }


    @Override
    public Iterator<MyPropertyValue> iterator() {
        return Collections.unmodifiableList(this.propertyValueList).iterator();
    }

    @Override
    public Spliterator<MyPropertyValue> spliterator() {
        return Spliterators.spliterator(this.propertyValueList, 0);
    }

    @Override
    public Stream<MyPropertyValue> stream() {
        return this.propertyValueList.stream();
    }

    @Override
    public MyPropertyValue[] getPropertyValues() {
        return this.propertyValueList.toArray(new MyPropertyValue[0]);
    }

    @Override
    @Nullable
    public MyPropertyValue getPropertyValue(String propertyName) {
        for (MyPropertyValue pv : this.propertyValueList) {
            if (pv.getName().equals(propertyName)) {
                return pv;
            }
        }
        return null;
    }

    /**
     * Get the raw property value, if any.
     * @param propertyName the name to search for
     * @return the raw property value, or {@code null} if none found
     * @since 4.0
     * @see #getPropertyValue(String)
     * @see PropertyValue#getValue()
     */
    @Nullable
    public Object get(String propertyName) {
        MyPropertyValue pv = getPropertyValue(propertyName);
        return (pv != null ? pv.getValue() : null);
    }

    @Override
    public MyPropertyValues changesSince(MyPropertyValues old) {
        MyMutablePropertyValues changes = new MyMutablePropertyValues();
        if (old == this) {
            return changes;
        }

        // for each property value in the new set
        for (MyPropertyValue newPv : this.propertyValueList) {
            // if there wasn't an old one, add it
            MyPropertyValue pvOld = old.getPropertyValue(newPv.getName());
            if (pvOld == null || !pvOld.equals(newPv)) {
                changes.addPropertyValue(newPv);
            }
        }
        return changes;
    }

    @Override
    public boolean contains(String propertyName) {
        return (getPropertyValue(propertyName) != null ||
                (this.processedProperties != null && this.processedProperties.contains(propertyName)));
    }

    @Override
    public boolean isEmpty() {
        return this.propertyValueList.isEmpty();
    }


    /**
     * Register the specified property as "processed" in the sense
     * of some processor calling the corresponding setter method
     * outside of the PropertyValue(s) mechanism.
     * <p>This will lead to {@code true} being returned from
     * a {@link #contains} call for the specified property.
     * @param propertyName the name of the property.
     */
    public void registerProcessedProperty(String propertyName) {
        if (this.processedProperties == null) {
            this.processedProperties = new HashSet<>(4);
        }
        this.processedProperties.add(propertyName);
    }

    /**
     * Clear the "processed" registration of the given property, if any.
     * @since 3.2.13
     */
    public void clearProcessedProperty(String propertyName) {
        if (this.processedProperties != null) {
            this.processedProperties.remove(propertyName);
        }
    }

    /**
     * Mark this holder as containing converted values only
     * (i.e. no runtime resolution needed anymore).
     */
    public void setConverted() {
        this.converted = true;
    }

    /**
     * Return whether this holder contains converted values only ({@code true}),
     * or whether the values still need to be converted ({@code false}).
     */
    public boolean isConverted() {
        return this.converted;
    }
}
